Crystallization and preliminary X-ray diffraction studies of the lectin from Erythrina corallodendron.

The lectin from Erythrina corallodendron, specific for N-acetyllactosamine, crystallizes in the hexagonal space group P6(1) (P6(5)) with unit cell dimensions a = b = 136.3 A, c = 83.2 A and one dimer of Mr 60,000 in the asymmetric unit. The crystals are suitable for high-resolution work.

Crystallization of a chymotrypsin inhibitor from Erythrina caffra seeds.

Crystals of a chymotrypsin inhibitor from Erythrina caffra seeds have been grown out of lithium sulfate, by the hanging drop method of vapor diffusion. The crystals belong to the rhombohedral space group R32, with a = 67.2 A and alpha = 99.4 degrees, and diffract to 3 A resolution.

[Evaluation of the protein quality of Erythrina edulis (balú)]. / Evaluación de la calidad de la proteína de la Erythrina edulis (balú).

The protein content (N x 6.25) of the seeds of Erythrina edulis (balú) varies between 18-21%; when the fraction corresponding to non-protein nitrogen is extracted with trichloroacetic acid (10%), this value decreases to 14-15%. Remarkable differences in the distribution of the protein fractions are observed when two schemes of extraction are assayed. The amino acid analysis shows that this legume has similar or higher amounts of most amino acids than those present in other leguminosae; the calculated chemical score and protein score show that methionine is the first limiting amino acid and tryptophan, the second. The protein efficiency ratio (PER) of thermically-treated flours has the highest value at 30 minutes of treatment (1.15).

Sigmoidin F, a new prenylated flavonoid from Erythrina sigmoidea.

Sigmoidin F, a new prenylated flavanone, as well as abyssinone IV and 5,7,4'-trihydroxy-3'-methoxy-5'-(1"-prenyl) flavonone have been isolated from the stem and bark of Erythrina sigmoidea. The structure of 1 has been confirmed by a combination of 1H-nmr and other spectroscopic techniques.

Cocculitine, a new abnormal Erythrina alkaloid from Cocculus laurifolius.

Cocculitine, C18H23NO3, mp 142-143 degrees, [alpha]25D+93 degrees (MeOH), a new abnormal Erythrina alkaloid has been isolated from the leaves of Cocculus laurifolius and has been assigned structure 1 on the basis of spectroscopic studies and chemical correlation.

Extractives from Erythrina eriotriocha.

From the stem bark of Erythrina eriotriocha, a novel isoflavone, eriotriochin has been isolated and characterized, in addition to known compounds auriculatin, dihydroauriculatin, and 3'-O-methylorobol. The structure of compound 1 was determined by COSY, selective INEPT, 2D HMBC, NOESY, DEPT, and other spectroscopic techniques.

Purification and some properties of two proteinase inhibitors (DE-1 and DE-3) from Erythrina latissima (broad-leaved erythrina) seed.

Two proteinase inhibitors, DE-1 and DE-3, were purified from Erythrina latissima seeds. Whereas DE-1 inhibits bovine chymotrypsin and not bovine trypsin, DE-3 inhibits trypsin but not chymotrypsin. The molecular weights and the amino acid compositions of the two inhibitors resemble the corresponding properties of the Kunitz-type proteinase inhibitors. The N-terminal primary structure of DE-3 showed homology with soybean trypsin inhibitor (Kunitz) and also with the proteinase inhibitors (A-II and B-II) from Albizzia julibrissin seed.

Purification and properties of the proteinase inhibitors from Erythrina caffra (coast Erythrina) seed.

1. Four proteinase inhibitors (DE-1 to DE-4) were purified from Erythrina caffra seed by gel filtration on Sephadex G-50 followed by ion-exchange chromatography involving DEAE-cellulose and DEAE-sepharose. 2. They comprise 164-166 amino acid residues (mol. wt 18,100) including 4 half-cystine residues and resemble the Kunitz-type proteinase inhibitors. 3. The N-terminal primary structure of DE-3 revealed also homology with those of the Kunitz-type inhibitors. For DE-1, DE-2 and DE-4 no free N-terminal amino acid was found. 4. DE-1 contains a potent inhibitor for both porcine trypsin and bovine alpha-chymotrypsin. Whereas DE-2 inhibits alpha-chymotrypsin strongly and has practically no action on trypsin, DE-3 inhibits both trypsin and alpha-chymotrypsin strongly. DE-4 is a potent inhibitor for trypsin but it binds alpha-chymotrypsin only weakly.

Purification and some properties of two proteinase inhibitors from Erythrina acanthocarpa seed.

Two proteinase inhibitors (DE-1 and DE-2) were purified from Erythrina acanthocarpa seed by gel filtration followed by ion exchange chromatography on DEAE-cellulose and DEAE-sepharose. They contain 163-164 amino acids (molecular weight 18000) including four half-cystine residues and resemble the Kunitz-type proteinase inhibitors. The N-terminal amino acid sequence of DE-1 also shows homology with those of the Kunitz-type inhibitors. For DE-2 no free N-terminal amino acid was found. DE-1 contains a potent inhibitor for both porcine trypsin and bovine alpha-chymotrypsin. Inhibitor DE-2 inhibits alpha-chymotrypsin strongly and it has practically no action on trypsin.